JDK VS Kotest

Compare JDK vs Kotest and see what are their differences.

JDK

JDK main-line development https://openjdk.org/projects/jdk (by openjdk)

Kotest

Powerful, elegant and flexible test framework for Kotlin with additional assertions, property testing and data driven testing (by kotest)
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JDK Kotest
191 17
18,393 4,282
2.1% 1.4%
10.0 9.4
about 14 hours ago 6 days ago
Java Kotlin
GNU General Public License v3.0 only Apache License 2.0
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.

JDK

Posts with mentions or reviews of JDK. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2024-04-19.
  • JEP draft: Exception handling in switch
    6 projects | news.ycombinator.com | 19 Apr 2024
  • Java 23: The New Features Are Officially Announced
    5 projects | news.ycombinator.com | 17 Apr 2024
    Completely gutted from the OpenJDK, last I checked. See here for the culprit PR: https://github.com/openjdk/jdk/pull/18688
  • macOS 14.4 might break Java on your machine
    4 projects | news.ycombinator.com | 18 Mar 2024
    > Yes, they're changing one aspect of signal handler use to work around this problem. They're not stopping the use of signal handlers in general. Hotspot continues to use signals for efficiency in general. See https://github.com/openjdk/jdk/blob/9059727df135dc90311bd476...

    This whole thread is about SIGSEGV, and specifically their SIGSEGV handling. However, catching normal signals is not about efficiency.

    Some of their exception handling is still odd: There is no reason for a program that receives SIGILL to ever attempt continuing. But others is fine, like catching SIGFPE to just forward an exception to the calling code.

    (Sure, you could construct an argument to say that this is for efficiency if you considered the alternative to be implementing floating point in software so that all exceptions exist in user-space, but hardware floating point is the norm and such alternative would be wholly unreasonable.)

    > The wonderful thing about choosing not to care about facts is having whatever opinions you want.

    I appreciate the irony of you making such statement, proudly thinking that your opinion equals fact, and therefore any other opinion is not.

    This discussion is nothing but subjective opinion vs. subjective opinion. Facts are (hopefully, as I can only speak for myself) inputs to both our opinions, but no opinion about "good" or "bad", "nasty" or not can ever be objective. Objective code quality does not exist.

  • The Return of the Frame Pointers
    6 projects | news.ycombinator.com | 17 Mar 2024
    I remember talking to Brendan about the PreserveFramePointer patch during my first months at Netflix in 2015. As of JDK 21, unfortunately it is no longer a general purpose solution for the JVM, because it prevents a fast path being taken for stack thawing for virtual threads: https://github.com/openjdk/jdk/blob/d32ce65781c1d7815a69ceac...
  • JDK-8180450: secondary_super_cache does not scale well
    1 project | news.ycombinator.com | 14 Mar 2024
  • The One Billion Row Challenge
    10 projects | news.ycombinator.com | 3 Jan 2024
  • AVX2 intrinsics for Arrays.sort methods (int, float arrays)
    1 project | news.ycombinator.com | 16 Dec 2023
  • A gentle introduction to two's complement
    1 project | news.ycombinator.com | 23 Nov 2023
  • Java JEP 461: Stream Gatherers
    3 projects | news.ycombinator.com | 3 Nov 2023
    Map doesn't implement the Collection interface.

    https://github.com/openjdk/jdk/blob/master/src/java.base/sha...

  • C++23: Removing garbage collection support
    3 projects | news.ycombinator.com | 1 Nov 2023
    C++ lets you write anything you can imagine, and the language features and standard library often facilitate that. The committee espouses the view that they want to provide many "zero [runtime] cost," abstractions. Anybody can contribute to the language, although the committee process is often slow and can be political, each release the surface area and capability of the language gets larger.

    I believe Hazard Pointers are slated for C++26, and these will add a form "free later, but not quite garbage collection" to the language. There was a talk this year about using hazard pointers to implement a much faster std::shared_ptr.

    It's a language with incredible depth because so many different paradigms have been implemented in it, but also has many pitfalls for new and old users because there are many different ways of solving the same problem.

    I feel that in C++, more than any other language, you need to know the actual implementation under the hood to use it effectively. This means knowing not just what the language specifies, but can occaissionally require knowing what GCC or Clang generate on your particular hardware.

    Many garbage collected languages are written in or have parts of their implementations in C++. See JS (https://github.com/v8/v8)and Java GC (https://github.com/openjdk/jdk/tree/36de19d4622e38b6c00644b0...)

    I am not an expert on Java (or C++), so if someone knows better or can add more please correct me.

Kotest

Posts with mentions or reviews of Kotest. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2023-11-29.
  • AocKt: Test-driven Advent of Code in Kotlin
    3 projects | /r/Kotlin | 29 Nov 2023
    As you might know, Advent of Code will begin this Friday! If, like me, you want to have a go at solving the puzzles in Kotlin, I would like to share with you a little library I've developed to reduce boilerplate and solve the puzzles in a test-driven approach. It is based on Kotest, a modern and Kotlin-first test framework.
  • Tests Everywhere - Kotlin
    4 projects | dev.to | 23 Nov 2023
    Kotlin testing with Kotest and MockK
  • Best practices for Unit Testing Android Apps with Mockk, Kotest and others
    5 projects | dev.to | 10 May 2023
    As a matter of fact, in the previous examples, we have shifted a bit away from the TDD standards in the meaning that we test not only the operability of our code, but rather check if the code runs according to certain specifications (Given/When/Then). These specifications are our tests, and the syntactic sugar in the form of the possibility to give clear names to the tests using DisplayName and the grouping of the tests by a set of similar attributes helps us clearly formulate these specifications. There is an entire family of frameworks in different languages that allow us to create such specifications: for Java it is Spock, for Ruby—RSpec, and for Kotlin—Spek and Kotest frameworks. Below, I will go into more detail about them.
  • Why do Kotlin tests (for Gradle projects) have to be inside classes?
    1 project | /r/Kotlin | 28 Jan 2023
  • Kotlin Mutation Tests
    1 project | /r/Kotlin | 25 Jan 2023
    I've tried so many times. SO MANY. I love the idea of mutation testing. Even chatGPT couldn't help me. It just made up fake mutation testing frameworks to try. To me, pitest is dead. kotest is not mutation testing, but it's property testing is the next best thing I have found to revolutionize your unit tests.
  • How to improve third-party libraries with Kotlin extensions
    2 projects | dev.to | 6 Dec 2022
    The extensions are not particularly useful in this scenario because the described functionality can be incorporated into the Host class. On the other hand, they flourish in test frameworks like Kotest and enable the rapid development of useful add-ons like custom matchers. Extending third-party libraries with utility functions is another prevalent use case. In the next sections, we'll zero in on this specific aspect.
  • Are there any plans to make a better build system for Kotlin than Gradle?
    4 projects | /r/Kotlin | 17 Sep 2022
  • Testing with fakes different states?
    1 project | /r/androiddev | 3 Aug 2022
    We're using Kotest for our unit tests and are quite happy with it.
  • Testing with Kotlin and JUnit5
    2 projects | dev.to | 10 Jun 2022
    Basic testing in Kotlin with Kotest built for kotlin specificatlly (upcoming)
  • Kotlin&Junit vs Groovy&Spock
    1 project | /r/Kotlin | 5 May 2022
    Here you are: https://github.com/kotest/kotest/issues/189

What are some alternatives?

When comparing JDK and Kotest you can also consider the following projects:

Graal - GraalVM compiles Java applications into native executables that start instantly, scale fast, and use fewer compute resources 🚀

spek - A specification framework for Kotlin

aircraft - The A32NX & A380X Project are community driven open source projects to create free Airbus aircraft in Microsoft Flight Simulator that are as close to reality as possible.

mockk - mocking library for Kotlin

steam-runtime - A runtime environment for Steam applications

Kluent - Fluent Assertion-Library for Kotlin

OkHttp - Square’s meticulous HTTP client for the JVM, Android, and GraalVM.

strikt - An assertion library for Kotlin

kitten - A statically typed concatenative systems programming language.

hamkrest - Hamcrest for Kotlin

intellij-community - IntelliJ IDEA Community Edition & IntelliJ Platform

mockito-kotlin - Using Mockito with Kotlin